Semiconductor device and method of forming overlapping semiconductor die with coplanar vertical interconnect structure

ABSTRACT

A semiconductor device is made by forming first and interconnect structures over a first semiconductor die. A third interconnect structure is formed in proximity to the first die. A second semiconductor die is mounted over the second and third interconnect structures. An encapsulant is deposited over the first and second die and first, second, and third interconnect structures. A backside of the second die is substantially coplanar with the first interconnect structure and a backside of the first semiconductor die is substantially coplanar with the third interconnect structure. The first interconnect structure has a height which is substantially the same as a combination of a height of the second interconnect structure and a thickness of the second die. The third interconnect structure has a height which is substantially the same as a combination of a height of the second interconnect structure and a thickness of the first die.

FIELD OF THE INVENTION

The present invention relates in general to semiconductor devices and,more particularly, to a semiconductor device and method of formingoverlapping semiconductor die with a coplanar vertical interconnectstructure for stacking semiconductor devices.

BACKGROUND OF THE INVENTION

Semiconductor devices are commonly found in modern electronic products.Semiconductor devices vary in the number and density of electricalcomponents. Discrete semiconductor devices generally contain one type ofelectrical component, e.g., light emitting diode (LED), small signaltransistor, resistor, capacitor, inductor, and power metal oxidesemiconductor field effect transistor (MOSFET). Integrated semiconductordevices typically contain hundreds to millions of electrical components.Examples of integrated semiconductor devices include microcontrollers,microprocessors, charged-coupled devices (CCDs), solar cells, anddigital micro-mirror devices (DMDs).

Semiconductor devices perform a wide range of functions such ashigh-speed calculations, transmitting and receiving electromagneticsignals, controlling electronic devices, transforming sunlight toelectricity, and creating visual projections for television displays.Semiconductor devices are found in the fields of entertainment,communications, power conversion, networks, computers, and consumerproducts. Semiconductor devices are also found in military applications,aviation, automotive, industrial controllers, and office equipment.

Semiconductor devices exploit the electrical properties of semiconductormaterials. The atomic structure of semiconductor material allows itselectrical conductivity to be manipulated by the application of anelectric field or through the process of doping. Doping introducesimpurities into the semiconductor material to manipulate and control theconductivity of the semiconductor device.

A semiconductor device contains active and passive electricalstructures. Active structures, including bipolar and field effecttransistors, control the flow of electrical current. By varying levelsof doping and application of an electric field or base current, thetransistor either promotes or restricts the flow of electrical current.Passive structures, including resistors, capacitors, and inductors,create a relationship between voltage and current necessary to perform avariety of electrical functions. The passive and active structures areelectrically connected to form circuits, which enable the semiconductordevice to perform high-speed calculations and other useful functions.

Semiconductor devices are generally manufactured using two complexmanufacturing processes, i.e., front-end manufacturing, and back-endmanufacturing, each involving potentially hundreds of steps. Front-endmanufacturing involves the formation of a plurality of die on thesurface of a semiconductor wafer. Each die is typically identical andcontains circuits formed by electrically connecting active and passivecomponents. Back-end manufacturing involves singulating individual diefrom the finished wafer and packaging the die to provide structuralsupport and environmental isolation.

One goal of semiconductor manufacturing is to produce smallersemiconductor devices. Smaller devices typically consume less power,have higher performance, and can be produced more efficiently. Inaddition, smaller semiconductor devices have a smaller footprint, whichis desirable for smaller end products. A smaller die size may beachieved by improvements in the front-end process resulting in die withsmaller, higher density active and passive components. Back-endprocesses may result in semiconductor device packages with a smallerfootprint by improvements in electrical interconnection and packagingmaterials.

The electrical interconnection between a wafer level chip scale package(WLCSP), package-on-package (PoP), and internal stacking module (ISM)containing semiconductor devices on multiple levels and external devicescan be accomplished with conductive through silicon vias (TSV), throughhole vias (THV), or conductive pillars. In most TSVs and THVs, thesidewalls and bottom-side of the via are conformally plated withconductive materials to enhance adhesion. The TSVs and THVs are thenfilled with another conductive material, for example, by copperdeposition through an electroplating process. The formation of TSVs andTHVs and integration of stacked packages through the verticalinterconnect structure is a costly part of the manufacturing process,which creates issues for highly competitive markets such as memory andapplication specific integrated circuits (ASIC).

SUMMARY OF THE INVENTION

A need exists to provide an interconnect structure for verticalintegration of semiconductor packages using a simple, low-costmanufacturing process. Accordingly, in one embodiment, the presentinvention is a method of making a semiconductor device comprising thesteps of providing a sacrificial carrier, forming a first conductivelayer over the sacrificial carrier, mounting a backside of a firstsemiconductor die over the first conductive layer, forming a firstsolder bump over a first contact pad of the first semiconductor die,forming a second solder bump over a second contact pad of the firstsemiconductor die, forming a third solder bump over the sacrificialcarrier in proximity to the first semiconductor die, mounting first andsecond contact pads of a second semiconductor die over the second andthird solder bumps, forming a second conductive layer over a backside ofthe second semiconductor die opposite the first and second contact padsof the second semiconductor die, depositing an encapsulant over thefirst and second semiconductor die and first, second, and third solderbumps, removing the sacrificial carrier, and removing a portion of theencapsulant to planarize the first solder bump and the backside of thesecond semiconductor die and planarize the third solder bump and thebackside of the first semiconductor die.

In another embodiment, the present invention is a method of making asemiconductor device comprising the steps of providing a firstsemiconductor component, forming first and second interconnectstructures over the first semiconductor component, forming a thirdinterconnect structure in proximity to the first semiconductorcomponent, and mounting a second semiconductor component over the secondand third interconnect structures. A backside of the secondsemiconductor die opposite the second and third interconnect structuresis substantially coplanar with the first interconnect structure. Abackside of the first semiconductor component opposite the first andsecond interconnect structures is substantially coplanar with the thirdinterconnect structure.

In another embodiment, the present invention is a method of making asemiconductor device comprising the steps of providing a firstsemiconductor component, forming first and second interconnectstructures over the first semiconductor component, forming a thirdinterconnect structure in proximity to the first semiconductorcomponent, and mounting a second semiconductor component over the secondand third interconnect structures. The first interconnect structure hasa height which is substantially the same as a combination of a height ofthe second interconnect structure and a thickness of the secondsemiconductor component. The third interconnect structure has a heightwhich is substantially the same as a combination of a height of thesecond interconnect structure and a thickness of the first semiconductorcomponent.

In another embodiment, the present invention is a semiconductor devicecomprising a first semiconductor component and first and secondinterconnect structures formed over the first semiconductor component. Athird interconnect structure is formed in proximity to the firstsemiconductor component. A second semiconductor component is mountedover the second and third interconnect structures. A backside of thesecond semiconductor die opposite the second and third interconnectstructures is substantially coplanar with the first interconnectstructure. A backside of the first semiconductor component opposite thefirst and second interconnect structures is substantially coplanar withthe third interconnect structure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a PCB with different types of packages mounted to itssurface;

FIGS. 2 a-2 c illustrate further detail of the representativesemiconductor packages mounted to the PCB;

FIGS. 3 a-3 e illustrate a process of forming overlapping die with acoplanar vertical interconnect structure;

FIG. 4 illustrates the overlapping die with multiple rows of solderbumps within the overlapping region; and

FIG. 5 illustrates stacked semiconductor devices electrically connectedthrough the coplanar vertical interconnect structure.

DETAILED DESCRIPTION OF THE DRAWINGS

The present invention is described in one or more embodiments in thefollowing description with reference to the figures, in which likenumerals represent the same or similar elements. While the invention isdescribed in terms of the best mode for achieving the invention'sobjectives, it will be appreciated by those skilled in the art that itis intended to cover alternatives, modifications, and equivalents as maybe included within the spirit and scope of the invention as defined bythe appended claims and their equivalents as supported by the followingdisclosure and drawings.

Semiconductor devices are generally manufactured using two complexmanufacturing processes: front-end manufacturing and back-endmanufacturing. Front-end manufacturing involves the formation of aplurality of die on the surface of a semiconductor wafer. Each die onthe wafer contains active and passive electrical components, which areelectrically connected to form functional electrical circuits. Activeelectrical components, such as transistors and diodes, have the abilityto control the flow of electrical current. Passive electricalcomponents, such as capacitors, inductors, resistors, and transformers,create a relationship between voltage and current necessary to performelectrical circuit functions.

Passive and active components are formed over the surface of thesemiconductor wafer by a series of process steps including doping,deposition, photolithography, etching, and planarization. Dopingintroduces impurities into the semiconductor material by techniques suchas ion implantation or thermal diffusion. The doping process modifiesthe electrical conductivity of semiconductor material in active devices,transforming the semiconductor material into an insulator, conductor, ordynamically changing the semiconductor material conductivity in responseto an electric field or base current. Transistors contain regions ofvarying types and degrees of doping arranged as necessary to enable thetransistor to promote or restrict the flow of electrical current uponthe application of the electric field or base current.

Active and passive components are formed by layers of materials withdifferent electrical properties. The layers can be formed by a varietyof deposition techniques determined in part by the type of materialbeing deposited. For example, thin film deposition may involve chemicalvapor deposition (CVD), physical vapor deposition (PVD), electrolyticplating, and electroless plating processes. Each layer is generallypatterned to form portions of active components, passive components, orelectrical connections between components.

The layers can be patterned using photolithography, which involves thedeposition of light sensitive material, e.g., photoresist, over thelayer to be patterned. A pattern is transferred from a photomask to thephotoresist using light. The portion of the photoresist patternsubjected to light is removed using a solvent, exposing portions of theunderlying layer to be patterned. The remainder of the photoresist isremoved, leaving behind a patterned layer. Alternatively, some types ofmaterials are patterned by directly depositing the material into theareas or voids formed by a previous deposition/etch process usingtechniques such as electroless and electrolytic plating.

Depositing a thin film of material over an existing pattern canexaggerate the underlying pattern and create a non-uniformly flatsurface. A uniformly flat surface is required to produce smaller andmore densely packed active and passive components. Planarization can beused to remove material from the surface of the wafer and produce auniformly flat surface. Planarization involves polishing the surface ofthe wafer with a polishing pad. An abrasive material and corrosivechemical are added to the surface of the wafer during polishing. Thecombined mechanical action of the abrasive and corrosive action of thechemical removes any irregular topography, resulting in a uniformly flatsurface.

Back-end manufacturing refers to cutting or singulating the finishedwafer into the individual die and then packaging the die for structuralsupport and environmental isolation. To singulate the die, the wafer isscored and broken along non-functional regions of the wafer called sawstreets or scribes. The wafer is singulated using a laser cutting toolor saw blade. After singulation, the individual die are mounted to apackage substrate that includes pins or contact pads for interconnectionwith other system components. Contact pads formed over the semiconductordie are then connected to contact pads within the package. Theelectrical connections can be made with solder bumps, stud bumps,conductive paste, or wirebonds. An encapsulant or other molding materialis deposited over the package to provide physical support and electricalisolation. The finished package is then inserted into an electricalsystem and the functionality of the semiconductor device is madeavailable to the other system components.

FIG. 1 illustrates electronic device 50 having a chip carrier substrateor PCB 52 with a plurality of semiconductor packages mounted on itssurface. Electronic device 50 may have one type of semiconductorpackage, or multiple types of semiconductor packages, depending on theapplication. The different types of semiconductor packages are shown inFIG. 1 for purposes of illustration.

Electronic device 50 may be a stand-alone system that uses thesemiconductor packages to perform one or more electrical functions.Alternatively, electronic device 50 may be a subcomponent of a largersystem. For example, electronic device 50 may be a graphics card,network interface card, or other signal processing card that can beinserted into a computer. The semiconductor package can includemicroprocessors, memories, application specific integrated circuits(ASICs), logic circuits, analog circuits, RF circuits, discrete devices,or other semiconductor die or electrical components.

In FIG. 1, PCB 52 provides a general substrate for structural supportand electrical interconnect of the semiconductor packages mounted on thePCB. Conductive signal traces 54 are formed over a surface or withinlayers of PCB 52 using evaporation, electrolytic plating, electrolessplating, screen printing, or other suitable metal deposition process.Signal traces 54 provide for electrical communication between each ofthe semiconductor packages, mounted components, and other externalsystem components. Traces 54 also provide power and ground connectionsto each of the semiconductor packages.

In some embodiments, a semiconductor device has two packaging levels.First level packaging is a technique for mechanically and electricallyattaching the semiconductor die to an intermediate carrier. Second levelpackaging involves mechanically and electrically attaching theintermediate carrier to the PCB. In other embodiments, a semiconductordevice may only have the first level packaging where the die ismechanically and electrically mounted directly to the PCB.

For the purpose of illustration, several types of first level packaging,including wire bond package 56 and flip chip 58, are shown on PCB 52.Additionally, several types of second level packaging, including ballgrid array (BGA) 60, bump chip carrier (BCC) 62, dual in-line package(DIP) 64, land grid array (LGA) 66, multi-chip module (MCM) 68, quadflat non-leaded package (QFN) 70, and quad flat package 72, are shownmounted on PCB 52. Depending upon the system requirements, anycombination of semiconductor packages, configured with any combinationof first and second level packaging styles, as well as other electroniccomponents, can be connected to PCB 52. In some embodiments, electronicdevice 50 includes a single attached semiconductor package, while otherembodiments call for multiple interconnected packages. By combining oneor more semiconductor packages over a single substrate, manufacturerscan incorporate pre-made components into electronic devices and systems.Because the semiconductor packages include sophisticated functionality,electronic devices can be manufactured using cheaper components and astreamlined manufacturing process. The resulting devices are less likelyto fail and less expensive to manufacture resulting in a lower cost forconsumers.

FIGS. 2 a-2 c show exemplary semiconductor packages. FIG. 2 aillustrates further detail of DIP 64 mounted on PCB 52. Semiconductordie 74 includes an active region containing analog or digital circuitsimplemented as active devices, passive devices, conductive layers, anddielectric layers formed within the die and are electricallyinterconnected according to the electrical design of the die. Forexample, the circuit may include one or more transistors, diodes,inductors, capacitors, resistors, and other circuit elements formedwithin the active region of semiconductor die 74. Contact pads 76 areone or more layers of conductive material, such as aluminum (Al), copper(Cu), tin (Sn), nickel (Ni), gold (Au), or silver (Ag), and areelectrically connected to the circuit elements formed withinsemiconductor die 74. During assembly of DIP 64, semiconductor die 74 ismounted to an intermediate carrier 78 using a gold-silicon eutecticlayer or adhesive material such as thermal epoxy. The package bodyincludes an insulative packaging material such as polymer or ceramic.Conductor leads 80 and wire bonds 82 provide electrical interconnectbetween semiconductor die 74 and PCB 52. Encapsulant 84 is depositedover the package for environmental protection by preventing moisture andparticles from entering the package and contaminating die 74 or wirebonds 82.

FIG. 2 b illustrates further detail of BCC 62 mounted on PCB 52.Semiconductor die 88 is mounted over carrier 90 using an underfill orepoxy-resin adhesive material 92. Wire bonds 94 provide first levelpacking interconnect between contact pads 96 and 98. Molding compound orencapsulant 100 is deposited over semiconductor die 88 and wire bonds 94to provide physical support and electrical isolation for the device.Contact pads 102 are formed over a surface of PCB 52 using a suitablemetal deposition such electrolytic plating or electroless plating toprevent oxidation. Contact pads 102 are electrically connected to one ormore conductive signal traces 54 in PCB 52. Bumps 104 are formed betweencontact pads 98 of BCC 62 and contact pads 102 of PCB 52.

In FIG. 2 c, semiconductor die 58 is mounted face down to intermediatecarrier 106 with a flip chip style first level packaging. Active region108 of semiconductor die 58 contains analog or digital circuitsimplemented as active devices, passive devices, conductive layers, anddielectric layers formed according to the electrical design of the die.For example, the circuit may include one or more transistors, diodes,inductors, capacitors, resistors, and other circuit elements withinactive region 108. Semiconductor die 58 is electrically and mechanicallyconnected to carrier 106 through bumps 110.

BGA 60 is electrically and mechanically connected to PCB 52 with a BGAstyle second level packaging using bumps 112. Semiconductor die 58 iselectrically connected to conductive signal traces 54 in PCB 52 throughbumps 110, signal lines 114, and bumps 112. A molding compound orencapsulant 116 is deposited over semiconductor die 58 and carrier 106to provide physical support and electrical isolation for the device. Theflip chip semiconductor device provides a short electrical conductionpath from the active devices on semiconductor die 58 to conductiontracks on PCB 52 in order to reduce signal propagation distance, lowercapacitance, and improve overall circuit performance. In anotherembodiment, the semiconductor die 58 can be mechanically andelectrically connected directly to PCB 52 using flip chip style firstlevel packaging without intermediate carrier 106.

FIGS. 3 a-3 e illustrate a process of forming a coplanar vertical(z-direction) interconnect structure for a wafer level chip scalepackage (WLCSP). In FIG. 3 a, a sacrificial substrate or carrier 150contains dummy or sacrificial base material such as silicon, polymer,polymer composite, metal, ceramic, glass, glass epoxy, beryllium oxide,or other suitable low-cost, rigid material or bulk semiconductormaterial for structural support. In one embodiment, carrier 150 is tapewith a stiffener frame.

An electrically conductive layer 152 is formed over carrier 150 usingpatterning with PVD, CVD, sputtering, electrolytic plating, electrolessplating process, or other suitable metal deposition process. Conductivelayer 152 can be one or more layers of Al, Cu, Sn, Ni, Au, Ag, Au—Ni, orother suitable electrically conductive material.

A backside of semiconductor die 154 is disposed over conductive layer152 with contact pads 156 a-156 b oriented upward. Alternatively,conductive layer 152 is formed over a backside of semiconductor die 154before mounting to carrier 150. Semiconductor die 154 includes asubstrate with an active region containing analog or digital circuitsimplemented as active devices, passive devices, conductive layers, anddielectric layers formed within the die and electrically interconnectedaccording to the electrical design and function of the die. For example,the circuit may include one or more transistors, diodes, and othercircuit elements formed within its active surface to implement basebandanalog circuits or digital circuits, such as digital signal processor(DSP), ASIC, memory, or other signal processing circuit. Semiconductordie 154 may also contain IPD, such as inductors, capacitors, andresistors, for RF signal processing. In another embodiment, a discretecomponent can be mounted on conductive layer 152 over carrier 150.

An electrically conductive material is deposited over contact pad 156 ausing an evaporation, electrolytic plating, electroless plating, balldrop, or screen printing process. The conductive material can be Al, Sn,Ni, Au, Ag, Pb, Bi, Cu, solder, and combinations thereof, with anoptional flux material. For example, the conductive material can beeutectic Sn/Pb, high-lead solder, or lead-free solder. The conductivematerial is bonded to contact pad 156 a using a suitable attachment orbonding process. In one embodiment, the conductive material is reflowedby heating the material above its melting point to form spherical ballsor bumps 158. In some applications, bumps 158 are reflowed a second timeto improve electrical connection to contact pad 156 a. The bumps canalso be compression bonded to contact pad 156 a. Bumps 158 represent onetype of vertical, z-direction interconnect structure that can be formedover contact pad 156 a. The interconnect structure can also use bondwires, conductive paste, stud bump, micro bump, or other electricalinterconnect.

In FIG. 3 c, an electrically conductive material is deposited overcontact pad 156 b and over carrier 150 in proximity to (within one diewidth) semiconductor die 154 using an evaporation, electrolytic plating,electroless plating, ball drop, or screen printing process. Theconductive material can be Al, Sn, Ni, Au, Ag, Pb, Bi, Cu, solder, andcombinations thereof, with an optional flux material. For example, theconductive material can be eutectic Sn/Pb, high-lead solder, orlead-free solder. The conductive material is bonded to contact pad 156 band over carrier 150 using a suitable attachment or bonding process. Inone embodiment, the conductive material is reflowed by heating thematerial above its melting point to form spherical ball or bump 160 andspherical ball or bump 162. The bumps can also be compression bonded.Bumps 160-162 represent one type of vertical, z-direction interconnectstructure that can be formed over contact pad 156 b and over carrier150. The interconnect structure can also use bond wires, conductivepaste, stud bump, micro bump, or other electrical interconnect.

A semiconductor die 164 is mounted over semiconductor die 154 withcontact pads 166 a-166 b oriented downward. Contact pads 166 a-166 belectrically connect to solder bumps 160 and 162, respectively.Semiconductor die 164 overlaps semiconductor die 154 by at least thearea of contact pads 156 b and 166 a. Semiconductor die 164 includes asubstrate with an active region containing analog or digital circuitsimplemented as active devices, passive devices, conductive layers, anddielectric layers formed within the die and electrically interconnectedaccording to the electrical design and function of the die. For example,the circuit may include one or more transistors, diodes, and othercircuit elements formed within its active surface to implement basebandanalog circuits or digital circuits, such as DSP, ASIC, memory, or othersignal processing circuit. Semiconductor die 164 may also contain IPD,such as inductors, capacitors, and resistors, for RF signal processing.In another embodiment, a discrete component can be mounted over solderbumps 160 and 162.

A conductive layer 168 is formed over a backside of semiconductor die164, opposite contact pads 166 a-166 b, using patterning with PVD, CVD,sputtering, electrolytic plating, electroless plating process, or othersuitable metal deposition process. Conductive layer 168 can be one ormore layers of Al, Cu, Sn, Ni, Au, Ag, Au—Ni, or other suitableelectrically conductive material.

FIG. 3 d shows an encapsulant or molding compound 170 deposited overcarrier 150, semiconductor die 154 and 164, and around solder bumps 158,160, and 162 using a paste printing, compressive molding, transfermolding, liquid encapsulant molding, vacuum lamination, or othersuitable applicator. Encapsulant 170 can be polymer composite material,such as epoxy resin with filler, epoxy acrylate with filler, or polymerwith proper filler. Encapsulant 170 is non-conductive andenvironmentally protects the semiconductor device from external elementsand contaminants. Die attach adhesive is not required for semiconductordie 154 and 164.

In FIG. 3 e, carrier 150 is removed by chemical etching, mechanicalpeel-off, CMP, mechanical grinding, thermal bake, laser scanning, or wetstripping. A portion of encapsulant 170 is removed by an etching processto expose solder bumps 158 and 162 and planarize solder bump 158 to thebackside of semiconductor die 164, including conductive layer 168, andplanarize solder bump 162 to the backside of semiconductor die 154,including conductive layer 152. The height of solder bump 158 is madesubstantially the same as the combination of the height of solder bump160 and thickness of semiconductor die 164. Likewise, the height ofsolder bump 162 is made substantially the same as the combination of theheight of solder bump 160 and thickness of semiconductor die 154.Accordingly, in semiconductor device 172, the exposed portion of solderbump 158 is substantially coplanar with the backside of semiconductordie 164, including conductive layer 168. On the opposite surface ofsemiconductor device 172, the exposed portion of solder bump 162 issubstantially coplanar with the backside of semiconductor die 154,including conductive layer 152. The coplanarity of the opposite surfacesof semiconductor device 172, including the z-direction interconnectstructure 158, 160, and 162, are suitable for stacking a plurality ofsemiconductor devices 172.

Semiconductor die 154 and 164 are flip chip type semiconductor die.Since semiconductor die 154 and 164 overlap and share common solder bump160, the width of semiconductor device 172 is reduced as compared to twoside-by-side semiconductor die.

FIG. 4 shows an embodiment with a plurality of rows of solder bumps 160electrically connecting semiconductor die 154 and 164. Solder bump 160 ais disposed between contact pads 156 b and 166 a, and solder bump 160 bis disposed between contact pads 156 c and 166 b. In this embodiment,semiconductor die 154 and 164 overlap by at least the area needed forthe multiple rows of solder bumps 160.

FIG. 5 shows a plurality of semiconductor devices 172 a-172 d verticallystacked over PCB 180. Solder bump 162 of semiconductor device 172 a iselectrically connected to interconnect site 178 a of PCB 180 usingsolder paste 176. Conductive layer 152 of semiconductor device 172 a iselectrically connected to interconnect site 178 b of PCB 180. Solderbump 158 of semiconductor device 172 a is electrically connected tosolder bump 162 of semiconductor device 172 b using solder paste 176.Conductive layer 168 of the semiconductor device 172 a is electricallyconnected to conductive layer 152 of the semiconductor device 172 busing solder paste 176. Solder bump 158 of semiconductor device 172 b iselectrically connected to solder bump 162 of semiconductor device 172 cusing solder paste 176. Conductive layer 168 of the semiconductor device172 b is electrically connected to conductive layer 152 of thesemiconductor device 172 c using solder paste 176. Solder bump 158 ofsemiconductor device 172c is electrically connected to solder bump 162of semiconductor device 172 d using solder paste 176. Conductive layer168 of the semiconductor device 172 c is electrically connected toconductive layer 152 of the semiconductor device 172 d using solderpaste 176.

The above described stacking technique for semiconductor device 172containing overlapping semiconductor die 154 and 164 with coplanarinterconnect structure is suitable for WLCSP, package-on-package (PoP),and internal stacking module (ISM). In particular, the device stackingis suitable for memory devices and application specific integratedcircuits (ASIC) because of the low profile package thickness and lowmanufacturing cost.

While one or more embodiments of the present invention have beenillustrated in detail, the skilled artisan will appreciate thatmodifications and adaptations to those embodiments may be made withoutdeparting from the scope of the present invention as set forth in thefollowing claims.

1. A method of making a semiconductor device, comprising: providing asacrificial carrier; forming a first conductive layer over thesacrificial carrier; mounting a backside of a first semiconductor dieover the first conductive layer; forming a first conductive bump over afirst contact pad of the first semiconductor die; forming a secondconductive bump over a second contact pad of the first semiconductordie; forming a third conductive bump over the sacrificial carrier inproximity to the first semiconductor die; mounting first and secondcontact pads of a second semiconductor die over the second and thirdconductive bumps; forming a second conductive layer over a backside ofthe second semiconductor die opposite the first and second contact padsof the second semiconductor die; depositing an encapsulant over thefirst and second semiconductor die and first, second, and thirdconductive bumps; removing the sacrificial carrier; and removing aportion of the encapsulant to planarize the first conductive bump andthe backside of the second semiconductor die and planarize the thirdconductive bump and the backside of the first semiconductor die.
 2. Themethod of claim 1, wherein the first conductive bump has a height whichis substantially the same as a combination of a height of the secondconductive bump and a thickness of the second semiconductor die, and thethird conductive bump has a height which is substantially the same as acombination of a height of the second conductive bump and a thickness ofthe first semiconductor die.
 3. The method of claim 1, furtherincluding: stacking a plurality of the semiconductor devices; andelectrically connecting the semiconductor devices through the first andthird conductive bumps and first and second conductive layers.
 4. Themethod of claim 1, wherein the first and second semiconductor die havean overlapping region.
 5. The method of claim 4, further includingforming a plurality of rows of the second conductive bumps between theoverlap region of the first and second semiconductor die.
 6. A method ofmaking a semiconductor device, comprising: providing a firstsemiconductor component; forming first and second conductiveinterconnect structures over the first semiconductor component; forminga third conductive interconnect structure in proximity to the firstsemiconductor component; and mounting a second semiconductor componentover the second and third conductive interconnect structures, wherein abackside of the second semiconductor component opposite the second andthird conductive interconnect structures is substantially coplanar withthe first conductive interconnect structure, and a backside of the firstsemiconductor component opposite the first and second conductiveinterconnect structures is substantially coplanar with the thirdconductive interconnect structure.
 7. A method of making a semiconductordevice, comprising: providing a first semiconductor component; formingfirst and second interconnect structures over the first semiconductorcomponent; forming a third interconnect structure in proximity to thefirst semiconductor component; mounting a second semiconductor componentover the second and third interconnect structures, wherein a backside ofthe second semiconductor component opposite the second and thirdinterconnect structures is substantially coplanar with the firstinterconnect structure, and a backside of the first semiconductorcomponent opposite the first and second interconnect structures issubstantially coplanar with the third interconnect structure; depositingan encapsulant over the first and second semiconductor components andfirst, second, and third interconnect structures; and removing a portionof the encapsulant to planarize the first interconnect structure and thebackside of the second semiconductor component and planarize the thirdinterconnect structure and the backside of the first semiconductorcomponent.
 8. The method of claim 6, wherein the conductive interconnectstructure includes a solder bump, conductive pillars, stud bump, ormicro bump.
 9. The method of claim 6, further including: forming a firstconductive layer over the backside of the first semiconductor component;and forming a second conductive layer over the backside of the secondsemiconductor component.
 10. The method of claim 6, wherein the firstand second semiconductor components have an overlapping region.
 11. Themethod of claim 10, further including forming a plurality of rows of thesecond conductive interconnect structure between the overlap region ofthe first and second semiconductor components.
 12. The method of claim6, wherein the first conductive interconnect structure has a heightwhich is substantially the same as a combination of a height of thesecond conductive interconnect structure and a thickness of the secondsemiconductor component, and the third conductive interconnect structurehas a height which is substantially the same as a combination of aheight of the second conductive interconnect structure and a thicknessof the first semiconductor component.
 13. The method of claim 6, furtherincluding: stacking a plurality of the semiconductor devices; andelectrically connecting the semiconductor devices through the first andthird conductive interconnect structures.
 14. A method of making asemiconductor device, comprising: providing a first semiconductorcomponent; forming first and second conductive interconnect structuresover the first semiconductor component; forming a third conductiveinterconnect structure in proximity to the first semiconductorcomponent; and mounting a second semiconductor component over the secondand third conductive interconnect structures, wherein the firstconductive interconnect structure has a height which is substantiallythe same as a combination of a height of the second conductiveinterconnect structure and a thickness of the second semiconductorcomponent, and the third conductive interconnect structure has a heightwhich is substantially the same as a combination of a height of thesecond conductive interconnect structure and a thickness of the firstsemiconductor component.
 15. A method of making a semiconductor device,comprising: providing a first semiconductor component; forming first andsecond interconnect structures over the first semiconductor component;forming a third interconnect structure in proximity to the firstsemiconductor component; mounting a second semiconductor component overthe second and third interconnect structures, wherein the firstinterconnect structure has a height which is substantially the same as acombination of a height of the second interconnect structure and athickness of the second semiconductor component, and the thirdinterconnect structure has a height which is substantially the same as acombination of a height of the second interconnect structure and athickness of the first semiconductor component; depositing anencapsulant over the first and second semiconductor components andfirst, second, and third interconnect structures; and removing a portionof the encapsulant to planarize the first interconnect structure and thebackside of the second semiconductor component and planarize the thirdinterconnect structure and the backside of the first semiconductorcomponent.
 16. The method of claim 14, wherein the conductiveinterconnect structure includes a solder bump, conductive pillars, studbump, or micro bump.
 17. The method of claim 14, further includingforming a first conductive layer over a backside of the firstsemiconductor component opposite the first and second conductiveinterconnect structures.
 18. The method of claim 17, further includingforming a second conductive layer over a backside of the secondsemiconductor component opposite the second and third conductiveinterconnect structures.
 19. The method of claim 14, further including:stacking a plurality of the semiconductor devices; and electricallyconnecting the semiconductor devices through the first and thirdconductive interconnect structures.
 20. A method of making asemiconductor device, comprising: providing a carrier; mounting a firstsemiconductor component to the carrier; providing a first conductivestructure over the first semiconductor component; mounting a secondsemiconductor component over the first semiconductor component usingsecond and third conductive structures, the second conductive structuredisposed between the first semiconductor component and the secondsemiconductor component, the third conductive structure disposed betweenthe carrier and the second semiconductor component; depositing anencapsulant over the first and second semiconductor components andfirst, second, and third conductive structures; and removing a portionof the encapsulant to planarize the first conductive structure and abackside of the second semiconductor component and to planarize thethird conductive structure and a backside of the first semiconductorcomponent.
 21. The method of claim 20, wherein the first conductivestructure has a height that is substantially the same as a combinationof a height of the second conductive structure and a thickness of thesecond semiconductor component, and the third conductive structure has aheight that is substantially the same as a combination of a height ofthe second conductive structure and a thickness of the firstsemiconductor component.
 22. The method of claim 20, wherein theconductive structure comprises a conductive pillar.
 23. The method ofclaim 20, further comprising forming a first conductive layer over thebackside of the first semiconductor component opposite the first andsecond conductive structures.
 24. The method of claim 20, furthercomprising forming a second conductive layer over the backside of thesecond semiconductor component opposite the second and third conductivestructures.
 25. The method of claim 20, further comprising: stacking aplurality of the semiconductor devices; and electrically connecting thesemiconductor devices through the first and third conductive structures.26. A method making a semiconductor device, comprising: providing acarrier; mounting a first semiconductor component to the carrier;providing a first conductive structure over the first semiconductorcomponent; mounting a second semiconductor component over the firstconductive component and over the carrier using a second conductivestructure and a third conductive structure, respectively; depositing anencapsulant over the first and second semiconductor components andfirst, second, and third conductive structures; and removing a portionof the encapsulant to planarize the first conductive structure and abackside of the second semiconductor component and to planarize thethird conductive structure and a backside of the first semiconductorcomponent.
 27. The method of claim 26, wherein the first conductivestructure has a height that is substantially the same as a combinationof a height of the second conductive structure and a thickness of thesecond semiconductor component, and the third conductive structure has aheight that is substantially the same as a combination of a height ofthe second conductive structure and a thickness of the firstsemiconductor component.
 28. The method of claim 26, wherein theconductive structure comprises a conductive bump.
 29. The method ofclaim 26, further comprising forming a first conductive layer over thebackside of the first semiconductor component opposite the first andsecond conductive structures.
 30. The method of claim 26, furthercomprising forming a second conductive layer over the backside of thesecond semiconductor component opposite the second and third conductivestructures.
 31. The method of claim 26, further comprising: stacking aplurality of the semiconductor devices; and electrically connecting thesemiconductor devices through the first and third conductive structures.